Although not yet peer-reviewed, the research was presented at the San Antonio Breast Cancer Symposium in December 2007. If the method proves to be both effective and safe, it has the potential for replacing implants for both reconstruction and breast enhancement procedures.

Nineteen cancer survivors participated in the study. All had had tumors and parts of their breasts removed. At Kyushu Central Hospital, Dr. Keizo Sugimachi used standard liposuction techniques to take fat from the participant's hips, thighs, and lower backs.

A portion of the fat was then processed via a system developed by a regenerative medicine company in San Diego, Cytori Therapeutics, that was also the sponsor of the study. Stem cells with the capability of becoming new breast tissue were extracted, combined with the remainder of the fat material, and injected in the subject's breasts.

On average, the tissues that had been treated gained from 6 to 16 millimeters of thickness initially with approximately two millimeters of shrinkage over a six month period. Overall, however, the thickness gained as a result of the injection was maintained for the long term.

Currently enhancement techniques use fat grafts or implants filled with silicone or saline. The fat grafts, however, have a tendency to collapse and to result in scarring whereas the implants can break, also causing disfigurement.

In the Japanese study the only side effect reported from the injection was a temporary hardening of tissue surrounding the injection site. The majority of the women in the study said the results achieved were satisfactory to them.